Vending Machine Having LED Lamp with Control and Communication Circuits

ABSTRACT

A vending machine includes a controller with an interface to control vending machine peripherals including an integrated LED lamp assembly having a plurality of light emitting diodes (LEDs) and a DC power connector to connect to a source of DC power within the vending machine. A power regulating circuit adjustably controls the amount of power provided to the LEDs in response to vending machine standard control signals received from the vending machine via a communication circuit compatible with the vending machine controller interface.

The present application is a continuation of and claims the benefit ofU.S. application Ser. No. 14/515,788 filed Oct. 16, 2014 which is adivisional of and claims the benefit of U.S. application Ser. No.11/552,307 filed Oct. 24, 2006 which issued as U.S. Pat. No. 8,905,579,all of which are incorporated by reference herein in their entirety.

FIELD OF THE INVENTION

The present invention relates to providing an efficient, long lifealternative to conventional light sources that provides added valuecontrol capabilities. More specifically, the present invention can beused as a fluorescent lamp alternative in a vending machine to reduceenergy use, improve safety, extend life, and allow attention getting useof the machine lighting. Additionally, by adding intelligence (in theform of a control circuit) to the light source, the machine controllercan accommodate specific energy and lighting needs through simplecontrol interfaces.

BACKGROUND OF THE INVENTION

The current trends toward increased efficiency, environmentalfriendliness, and higher quality longer life products makes thetransition to LED based lighting more and more prevalent. The use of LEDlighting in automobile lights, traffic lights, and even incandescentlight replacements is a growing trend. There are a number of reasons theuse of LED lights has not been used as an alternative to fluorescentlamps including the inherent efficiency of fluorescent lamps. Typically,fluorescent lamps have a life of about 6000 hours. The LED replacementlamps would have a life of 30,000 to 50,000 hours. During the life ofLEDs the output can be held constant avoiding the degradation in lightand flickering seen in fluorescent lamps. Additionally, fluorescentlamps provide a soft uniform light which is particularly advantageous inapplications such as vending machines. The use of incandescent or evenLED lights are generally not used in vending machines as havingconsumers look into these light sources is uncomfortable and tends to beblinding, which would make viewing the products to be vended moredifficult. Looking into fluorescent lights does not generally have thiseffect, and hence improves the viewing of products. The presentinvention allows the use of LEDs while maintaining the advantages offluorescent lighting. The present invention also takes advantage of thedirectional characteristics of LEDs to provide more useful light outputwhere it is needed further improving the efficiency of the system.

The use of the present invention as a replacement for fluorescent lampshas a number of additional advantages. The current EU RoHS Directivebanning the use of environmentally problematic materials currentlyprovides an exception for fluorescent lamps. Without the exception,these lamps would not meet the requirements due to the levels of mercuryused in the manufacturing and required for the operation of these lamps.Therefore, the present invention provides an environmentally safealternative to the conventional lighting used in many applications, andin particular vending machines.

The use of the present invention as a replacement for fluorescent lampsalso addresses the increasing concern of safety and efficiency. In aneffort to improve the power efficiency of fluorescent lamps, theindustry has moved from conventional ballasts to electronic ballasts.Each of these has presented challenges and problems which still existand are particularly notable in applications serviced by untrainedpersonnel such as in vending machines. The conventional ballasts areinefficient. Electronic ballast are more efficient but considerably moreexpensive. However, they have been associated with a number of qualityproblems. These range from the annoying flashing of fluorescent lamps asthey age and cannot correctly power on, to arcing at the lamp socketsespecially when lamps are not correctly inserted resulting in thepotential for fire. LED based lamps would eliminate these issues.Another key advantage of the lamp of the current invention as areplacement for fluorescent lamps is the LED lamps will not present asafety concern if dropped or broken. Fluorescent lamps implode whenbroken, shattering glass and the environmentally unfriendly elementshoused within the lamps. LED lamps are based on solid state devices thathave no such concern.

A key element to the current invention is that the LED based lamp caninclude additional electronics to allow these lamps to be mechanicallyand electrically compatible with existing fluorescent lamps. In thesecases, the LED based lamps can be direct replacements for existingfluorescent lamps in applications such as current vending machines. Thiswould allow most of the benefits of using the LED lamps to be realizedwithout having to re-wire existing lighting systems or replacingexisting ballasts. In most applications light is desired to be directedto an area limited to about 180 degrees or less. Standard fluorescentlamps emit light in 360 degrees which results in wasted energy or therequirement for reflectors to direct the light where needed. The currentinvention will direct light in a plane limited to about 180 degrees. Tooptimize the orientation of the LED lamp, adjustable pins used to securethe lamps into existing lamp sockets will allow the necessaryflexibility to direct the light where needed.

The current invention also anticipates the ability to control thelighting rather than just have it on continuously and at fullbrightness. This is achieved by adding intelligence to the LED lamp sothat it has a communications capability compatible with existingcommunication systems within the product or system with which the LEDlamp is intended to be used. In the case of vending machines, thiscommunications system can be MDB, RS232, DEX, infrared, inductive, RF,or the like. The advantages of providing such an intelligent lamp wouldbe to allow the existing controller, such as the existing vendingmachine controller, to control the operation of the machine lightingthrough the existing communication links. This would allow the lamp tobe turned on or off based on time, machine use, sensed approaching ofconsumers, or any such method. It would also allow the lamp to bedimmed, flashes, chased or any other special effects created as needed.One particular implementation of the current invention uses to multiplecolor LEDs to allow the creation of different colored light to begenerated also controllable through the communications link. Theparticular choice of Red, Green and Blue LEDs has the additional benefitof creating white light of selectable color temperature as well as thevarious colors achievable with the mixing of these primary colors. Theuse of color provides additional attention getting techniques to beapplied which will aid in the marketing of the products that may be in avending machine as an example.

In the case of a vending machine, the choice of MDB as a communicationslink is particularly attractive as this is the existing interfacestandard for all the peripherals in a vending machine. This includes thecoin, bill and card readers. The protocol already exists and issupported through NAMA, the industry trade association. Adding specificenhancements to this interface to allow vending controllers to have theability to achieve the control and leverage the features of the LED lampwould be a relatively simple process. The interface is not proprietaryso any machine manufacturer would be able to take advantage of this newtechnology.

In the broader context, the control of the intelligent LED lamp caninclude a wireless interface such as RF, IR or the like. The use ofwireless remote control opens the market options of providing efficientlighting to any environment so long as a source of power (low voltage orhigh voltage, AC or DC) is available. All the advantages of efficientcontrol of the lighting (time based turn on and off, use based turn onor off, dimming and color generation) are achievable without having torewire an existing facility or device.

The mechanical configuration of the LED lamp of the current invention isnot limited to just the fluorescent tube arrangement. However, even forthis arrangement, the LED lamps can be provided in fixed length “strips”which can be interconnected to provide various length lamps. Forexample, a 12″ lamp could be connected directly to a second 12″ lamp toprovide a 24″ lamp. This stackable design would allow maximumflexibility using standard lamp modules.

SUMMARY OF THE INVENTION

The present invention is intended to provide an LED based replacementfor fluorescent lamps, providing diffused light, and operable withexisting fluorescent lamp ballasts and directly compatible with existinglamp sockets, or without such preexisting connections and powersupplies, as a full replacement for other types of light sources. Thelamp assembly of the present invention operates with high energyefficiency on low voltage and includes a control circuit havingcommunications link, as well as remote and wireless control. The lampassembly of the present invention is dimmable, has built in flashing andsequencing ability as well as control of the color of the lightproduced. In order to accommodate many installation options, theassembly of the present invention provides a mechanicallyinterconnecting LED based lamp to allow multiple length lamps to becreated from a standard smaller size unit. Other features and advantagesof the present invention are described further below and will be readilyapparent by reference to the following detailed description andaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a perspective view of a presently preferred embodiment ofa LED based lamp suitable as a replacement fluorescent lamp inaccordance with the present invention.

FIG. 2 depicts an exploded view of a preferred configuration of themounting pins to allow adjustability when mounting in existing lampsockets.

FIG. 3 depicts an arrangement of fixed length LED lamp strips suitableto be interconnected to create lamps of increased length.

FIG. 4 depicts a block diagram of a standard fluorescent ballast andlamp wiring arrangement.

FIG. 5 depicts a block diagram of the control circuit electronicsassociated with the LED based lamp to be used as a replacement forfluorescent lamps in accordance with the present invention.

FIG. 6 depicts an electronics schematic for a preferred embodiment ofthe LED based lamp to be used as a replacement for fluorescent lamps inaccordance with the present invention.

FIGS. 7, 7-1, 7-2, 7-3, 7-4, 7-5, 7-6, 7-7 and 7-8 (collectively FIG. 7)depict an electronic schematic for a preferred embodiment of the LEDbased lamp with color control.

FIG. 8 depicts a chart of typical color LED specifications.

FIG. 9 depicts an LED lamp of the present invention with the vendingindustry standard MDB connectors.

FIG. 10 depicts an alternate configuration of LEDs suitable for use in afluorescent lamp replacement which has the ability to change colors.

FIGS. 11A and 11B depict a vending machine utilizing the LED based lampof the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a perspective view, 100, of a presently preferredembodiment of the current invention is shown. An array of white LEDs,102, are mounted to a printed circuit board, 103, that is then mountedto a metal extrusion, 104. A natural translucent white polystyrene lens,106, is used to cover the LEDs and act as a diffusing lens. The assemblyis terminated on both sides with pin terminals, 110, suitable to mountinto standard fluorescent sockets. This allows standard fluorescentbulbs to be replaced by the LED lamp designed for this purpose anddescribed in detail below. The terminals at the end of each of ends ofthe fluorescent lamp replacement assembly can be adjusted so theorientation of the lamp in the sockets is adjustable. This is best shownin FIG. 2. By positioning the end terminals 122 a and 122 b of the LEDlamp, the light output from the lamp can be directed in any position inincrements determined by the positioning wheel, 120 a and 120 b, fromthe standard mounting position. In a preferred embodiment of thefluorescent lamp mounting arrangement, the end terminals, 122 a and 122b, are screw machined parts with threads, 123, which screw into thepositioning wheels, 120 a and 120 b. The wires, 125,126 which are usedto connect the end terminals, 122 a and 122 b, to the circuit board,103, are terminated with ring terminals, 127 and 128, at one end and aconnector, 129, at the other end. The connector, 129, will plug into itsmate on the printed circuit board, 103. The terminal assembly is keyedto the mounting plates, 124 a and 124 b by pins shown in mounting plate124 b at 132 and then fastened by screws, 130 and 131. In a similarmanner, other standard fluorescent lamp sizes and terminations can beemulated to allow the lamp of the current invention to be used as areplacement for most fluorescent lamp styles.

An alternate assembly approach of the current invention is shown in FIG.3. In this arrangement, individual strings of LEDs or arrays of LEDs aremounted on a single printed circuit board as shown. Groups of thesecircuit boards can be interconnected to allow larger lamps to be createdfrom a group of LED arrays, 140, 141 and 142, such as the arrays of LEDsof FIG. 6, for example. Details related to the strings of LEDs andarrays of LEDs will be discussed below. These connectors are positionedso that a second LED assembly can be interconnected to the first makingan assembly twice as long. Additional assemblies can be interconnectedto provide increasing lengths of LED assemblies. This is particularlyuseful to allow replacement LED lamps to be designed with standard LEDassemblies to produce 18″, 24″, 32″ and other longer fluorescent bulbequivalents as well as in new design applications which are not bound byhaving to mount in standard fluorescent tube sockets, as in designingthe LED lamp into equipment using a low voltage interface such as theMDB interface used in vending machines. This will be discussed ingreater detail below.

Referring to FIG. 4, a typical standard fluorescent ballast andfluorescent lamp block diagram is shown. Fluorescent lamps use a ballastto limit the voltage and current to the lamp once the lamp is on.Initially, the ballast provides filament current to start the lamp alongwith the use of a starter 206. The starter 206 effectively shorts thelamp until the filaments are powered and a supply of electrons isgenerated, at which time the starter 206 becomes an open circuitallowing the electrons to flow through the fluorescent tube. Theelectrons bombard the fluorescent material coating the lamp turning onthe light. The details of operation of a fluorescent lamp are wellunderstood and are only presented in summary foil for reference. Otherballast arrangements are also used and will not be discussed here asthese are well known in the art. This typical arrangement is shown forillustrative purposes.

Typically, an 18 watt fluorescent lamp 203 would use a fluorescentballast 202 sourcing about 0.3 amps of current and having an inductanceof approximately 0.5 Henries. This ballast limits the voltage to thefluorescent lamp to approximately 60 volts when the lamp is “on” as itsreactance is approximately 200 ohms at 60 Hz. When the lamp is in thestarting mode, the full line voltage of 120 volts 201 appears across thelamp, and, a starter device energizes the filaments at both ends of thelamp to ionize the gas within the lamp. As the filaments ignite thegases in the lamp, the rapid excitation of the gas causes the lamp toturn on while acting as negative impedance. The ballast now limits thevoltage due to the inductive reactance of the ballast. An example ofsuch a ballast is the Advance Transformer Company catalogue numberLC-14-20C-20W.

A preferred mode of the current invention is an LED based device thatwould be able to be fitted into a standard Fluorescent lamp socket. Whenusing the LED lamp of the present invention, the starter 206 is removedfrom the fluorescent fixture. The LED fluorescent lamp replacement asshown in FIG. 5, in one embodiment would be mechanically compatible witha 24″ tube such as the F18T8/CW/K24 fluorescent lamp. This controlcircuit consists in its simplest form, of an AC to DC Converter 301 orBridge Rectifier, and a group of LEDs 303 connected in a series and/orparallel combination, depending upon the light output (power) desired.Further discussion on how these combinations are matched to the desiredfunctionality of the replaced Fluorescent Lamp follows below. In orderto have complete control over the light output of the LED replacementlamps, a current regulator circuit 302 can be added to the controlcircuit of the current invention to ensure the required current isdetermined by the lamp eliminating variations between ballasts. Thecurrent regulator circuit may be limited to a simple voltage limit tolimit the maximum current drawn by the LED devices in the LED lamp. Thiswill be discussed below in detail.

A more detailed look at a preferred embodiment of the present inventionis shown in FIG. 6. Referring to the lamp fixture 590, the existingfluorescent ballast 202 receives line voltage power 201 from a standard120 VAC power source (US standards are used in this preferredembodiment). The output of the ballast 202 and 120 VAC power source 201is supplied to the fluorescent lamp sockets 550 and 552. For the ballasttype shown, a starter 206 is used as described above and is shownterminating at the second terminal pins at each fluorescent sockets 550and 552. The present invention interfaces with the ballast 202 and powersource 201 through the existing lamp sockets 550 and 552. The output ofthe ballast 202 and power source 201 is an AC signal as discussed above.FIG. 6 includes a schematic representation of two LED lamp assemblies,140, 141 as earlier described in FIG. 3. A full wave diode bridge, 524and 534 is used in each of these LED lamp assemblies to convert the ACsignal to a DC signal to source the array of LEDs denoted by 520 a-p and530 a-p for each of the two LED assemblies shown. The use of a full wavebridge for this application is well known in the art and is notexplained further. A current balancing resistor 523 and 533 is in serieswith the diode bridges 524 and 534 respectively to balance the currentto be supplied to each of the LED arrays. As seen, voltage limiter 522and 532 limits the voltage to 60 volts using standard zener diodes asshown. The current supplied by the power source 201 and ballast 202combination is determined by the ballast 202 which acts as a currentlimiting inductor of 0.5 Henry. At the line frequency of 60 Hz, thecurrent capability of the ballast in the example of FIG. 6 is about 300mA. Since this current supplies two LED arrays 140 and 141, each ofthese have about 150 mA of current available. The voltage limiters 522,532 shown are 60 volt 5 watt zener diodes. These zener diodes assure thevoltage across the array of LEDs does not exceed their voltagespecifications. The typical voltage drop of white LEDs is 3.6V as shownin the chart in FIG. 8. The fifteen LEDs shown in each LED assembly 140and 141 will therefore drop 15×3.6V or 54 Volts. The voltage source ofthe ballast 202 and power source 201 supply will be able to support thisvoltage as the inductor (ballast 202) will absorb the excess voltageavailable. The use of inductors and ballasts for current limiting iswell known in the art and not further discussed here. The array of LEDsare shown in the preferred embodiment as two parallel combinations of 15LEDs, 140 and 141, each parallel combination having current balancingresistors 523 and 533 to ensure the current through each of the parallelcombinations of LEDs is approximately equal. Without these resistors,the current would divide based on the impedances differences of thearrays of LEDs which can be quite variable. The series combinations ofLEDs are shown as 520 a through 520 p and 530 a through 530 p. Each ofthe LEDs in the preferred embodiment is ½ watt rated and drop about 3.6volts. The two parallel combinations of LEDs are shown drawing about 150mA of current each.

As described above in reference to FIG. 3, the LED arrays can bepartitioned into individual assemblies to be interconnected to allow afamily of products of varying lengths to be easily made. The two LEDarrays of FIGS. 6, 140 and 141 each have their own diode bridge, 524 and534, as well as their own voltage limiters 522 and 532, optional fuses,525 and 535 as well as male and female connectors 526, 528, 536, 538 toallow for this interconnection. The lamp sockets, 129 in both are shownconnected to a male connector, 546 in 560. This male connector 546 wouldinterconnect to one of the female connectors 528 or 538 of the LEDarrays. If the female connector 528 were used, the male connector fromthis LED array would be interconnected to the female connector 538 ofthe second LED array. The male connector 536 of this second LED arraycan then be interconnected to a third LED array, not shown, or to thesocket 548 of assembly 580 which then interconnects to the other endlamp connector 129.

The current invention provides an LED lamp which can be controlled in anumber of ways including light intensity and color. The control circuitelectronics can be embedded inside the lamp or provided externallythrough an interface unit, or even implemented in the controller systemof the vending machine itself. FIG. 7 shows a preferred electronicsschematic for controlling the multicolor LED lamp. Three arrays of colorLEDs are used. To achieve full color capability it is well known in theart to use Red, Green and Blue to produce the color spectrum. Inaddition to production of colored light, various color temperatures ofwhite light may be produced to highlight the colors of productsilluminated in the vending machine.

In this design, there are three constant current supplies 701, 721 and741, one for each of the LED color arrays, namely Red 720, Green 730 andBlue 740 respectively. Each of these constant current supplies isindependently controlled to allow the proper mix of each of the colorsto produce any color required as described below. In order to allow therange of colors that may be desired from an LED “RGB” arrangement, someunique control techniques are required. The emitted wavelength from thechosen LED has to be known and consistent over the range of controlrequired. As specified, the wavelength of a specific LED as determinedby its manufacturer is at a specific current level. It is critical toensure the specified current is used for each LED type chosen for eachof the Red, Green and Blue LED arrays. The sample LED data sheet summaryshown in FIG. 8 shows the characteristics and specifications of each ofthe Red, Green and Blue LED's used in the preferred embodiment.Additionally, the specifications for an Amber LED are shown. Amber andother colors can be used in addition to or in place of three colors usedin the preferred embodiment. Each of these LED specifications indicatethe wavelength specified is at a current of 140 mA. The constant currentsupplies 701, 721, and 741 will each be set for 140 mA per LED string tomeet the manufacturer's specifications. An example LED string is shownin FIG. 7 for the Red array 720 as including LED 722, LED 724, and LED726. Current balancing resistor 770 is also part of this LED string.Depending on the number of such strings controlled by the constantcurrent supply 701, the total current required by the supply can bedetermined. The circuit shown in 701 is designed to supply up to 1 Ampof current, although the resistor ratio of resistor 707 and resistor 708anticipates three LED strings with a required current up to 420 mAmaximum.

The current to each LED string and to each LED array will be fixed atthis designed current so that when the switching supply 701 isconducting, independent of duty cycle, the current supplied is thespecified current. This current is supplied to the source voltage on theLED array and is determined by the constant current supply 701 at outputVREG RED. The duty cycle therefore determines what percent of the timethis fixed current is supplied. The duty cycle is controlled by thePulse Width Modulation Channel Controller 750 described below. Each ofthe three color LED analysis controlled similarly, optimized to ensurethe fixed current used is per the manufacturer's specificationsindependent of the duty cycle.

The details of the control of the current and duty cycle are furtherdescribed. The constant current switch-mode supplies are similar foreach of the three color LED arrays. The following description will berelative to the Red LED array 720 constant current switch-mode supply701, but applies to each of the other two supplies as well. The constantcurrent switch-mode supply is comprised of a Linear Technologies LT3474device 702, inductor 703 and diode 704 configured as a conventionalswitching supply well known in the art and not described in detail here.This circuit is capable of supplying 12 watts of power to an array ofLEDs. The device provides precise pulse by pulse current limiting, andalso provides an input for PWM modulation. This input cuts off allcurrent to the LED array during the PWM off time. So, when the LEDs areon, they receive their rated optimum operating current. In this design,each series leg of LEDs receives 140 milliamps of current when anycurrent flows. The total current supplied by the constant currentswitch-mode supply is determined by the resistors 707 and 708.

To control the intensity, a Microchip PIC16F737, 750 microcontrollerwith three PWM (Pulse Width Modulator) controllers is used. Each of thePWM controllers is delegated to a color, and, by changing the duty cycleof the PWM, the intensity of its corresponding color can be changed. PWM751 controls the Red LED array 720, PWM 752 controls the Green LED array730, and PWM 753 controls the Blue LED array 740.

The wavelengths of the LEDs used in the preferred embodiment are shownin FIG. 8. By no means is this device limited to the above wavelengths.By using a longer wavelength blue, for instance 485 nanometers, a higherefficiency Lamp can be made. Amber is given as an alternate to Red, asit can also enhance the efficiency of the Lamp if the deep red color(which the eye is not very sensitive to) is not required, or desired.

Small series resistance, nominally 5 ohms 770 through 778, is used tobalance the current in each leg of LED's. This balancing resistor isneeded so as to keep a leg of LED's with a low forward voltage fromrobbing all of the current of a series of LED's with a larger forwardvoltage. This eliminates having to select LED's with the same forwardvoltage drops to achieve the current balancing which would add to thecost of the LED's.

The electronic circuit described can be embedded in the LED circuitassembly so that the LED lamp is an integrated “smart” product.Communications to the smart LED lamp can be through any number ofgeneric or industry standard protocols. The LED replacement lamp of thecurrent invention can be used as a replacement for a fluorescent lamp asdescribed above, so long as the means to control the LED replacementlamp is provided. Alternatively, the lamp can be designed to work as areplacement for a fluorescent lamp and its ballast assembly by providinga power source directly to the lamp. This power source can be lowvoltage such as 24 VDC.

The actual color that will be perceived will be determined by the ratioof light power output from each of the three color LED arrays. The lightoutput of each of the LED arrays is also determined by the manufactureat the rated current. Therefore, the light output from each of the LEDarrays can be controlled relative to the other LED arrays by controllingtheir respective PWM duty cycle. Either a formula or look up table canbe used to define the duty cycle relationships between LED arrays tocreate any specific color output. The arrangement of the LED arraysalong with the diffusing lens “mixes” the light outputs to ensure thedesired color is produced. FIG. 10 shows a view of three LED arrayassemblies, 901, 902, and 903 with each assembly having a series ofalternating Blue, 906, Green, 905, and Red, 904, LEDs. The configurationof the multicolor LEDs can be in any arrangement suitable to producingoverlapping optical fields so they combine to form the desired colors.Alternatively, the LEDs can be multiplexed at high speed to provide thesame optical effect although only one LED may be on at a time. Thisallows for multi die LEDs to be used as well.

The vending industry, by way of example uses an MDB serial interfacebetween peripherals and the vending machine controller. One embodimentof the current invention is a lamp tailored to the vending industry andintended to be controlled by a vending machine controller. The MDBmaster, or any appropriate serial communication device, can communicatewith the Lamp PWM controller through this MDB interface, and change theintensity of each of the three colors, to produce color, change theintensity at a given color (or white) to achieve dimming, create specialattention getting effects such as flashing or chasing lights, or controlthe power to the lamp to turn it off when not required.

The vending industry standard interface, known as MDB is shownschematically in FIG. 7. The interface circuitry 800 provides both powerfrom the MDB interface including an unregulated input voltage, typically34 VDC, 801 and power return, 802. This power is used to power the LEDlamp. The 34 VDC input relative to the power return is input to avoltage regulator 804 preferably an industry standard part such as theLM320 series regulator supplied by multiple sources. A full wave bridge,304 is provided although not needed for this interface as the MDB inputis already DC voltage. However, the inclusion of the full wave bridgeallows low voltage AC to be used if insufficient power is available fromthe MDB source. A low voltage, 24 VAC supply could be used in place ofthe DC supply without any adjustments to the circuitry.

The MDB interface includes both transmit, 830, and receive, 820,circuitry to isolate these signals from the source vending controller.Opto isolators 811 and 821 are shown for this purpose. The use of optoisolators for this purpose is fully understood in the art. Of course anysuitable serial interface, optical interface, wireless interface, or thelike can be used to communicate to the smart LED lamp.

Referring to FIG. 9, LED lamp assembly, 800, is depicted with mountingbrackets 801 and 802 to allow an alternate mounting arrangement to thestandard fluorescent socket interface described above. Key hole, 803 and804 mounting allows the LED lamp to be mounted in either a vertical orhorizontal position. The length of the lamp can vary as discussed aboveusing the inter-connecting LED boards. The electronic interface isadapted to the application with the vending standard MDB connector set810 and 812 shown. This interface is described above. Clearly any typeof connector and interface protocol can be used to adapt the currentinvention to specific industry applications.

FIGS. 11A and B depict a vending machine 1100 (FIG. 11A) employing avending controller 1150 (FIG. 11B) mounted inside the vending machine,but shown separately for ease of illustration, to control peripherals1170, such as coin, bill, and card readers, also mounted internally, butshown externally for ease of illustration, utilizing a communicationsystem 1160 implementing a communication interface, such as the MBDinterface, or the like. As seen in FIG. 11B, the vending controller 1150also communicates with and controls an LED based lamp 1180 in accordancewith the present invention as addressed in detail above. Again, the LEDbased lamp 1180 is mounted internal to the vending machine 1100, butshown in the block diagram of FIG. 11B for ease of illustration. Forexample, lamp 1180 will typically be mounted above products to be vendedby the vending machine 1100. As further seen in FIG. 11B, lamp 1180 hasa DC power connector 1182 for connection to an existing source ofavailable DC power 1190 within the vending machine 1100.

While the invention has been described in its preferred embodiments, itis to be understood that the words which have been used are words ofdescription rather than of limitation and that changes may be madewithin the purview of the appended claims without departing from thetrue scope and spirit of the invention in its broader aspects. Rather,various modifications may be made in the details within the scope andrange of equivalents of the claims and without departing from the spiritof the invention. The inventors further require that the scope accordedtheir claims be in accordance with the broadest possible constructionavailable under the law as it exists on the date of filing hereof (andof the application from which this application obtains priority,) andthat no narrowing of the scope of the appended claims be allowed due tosubsequent changes in the law, as such a narrowing would constitute anex post facto adjudication, and a taking without due process or justcompensation.

1. A lamp assembly designed to illuminate products in a vending machine,the lamp assembly comprising one or more light emitting diodes, and acontrol circuit connected to the diodes, and to a source of power, thediodes and the circuit housed in a lamp housing having terminationsadapted to be mounted into a vending machine socket for a fluorescentlamp, the control circuit further comprising a communications circuitfor receiving control signals, the control circuit selectivelycontrolling adjustment of the illumination provided by the plurality oflight emitting diodes based upon said control signals. 2-10. (canceled)11. The lamp assembly of claim 1 wherein the lamp assembly is employedas a retrofit replacement for a fluorescent lamp of a preexistingvending machine without having to re-wire an existing lighting system.12. The lamp assembly of claim 1 wherein the lamp assembly is employedas a retrofit replacement for a fluorescent lamp of a preexistingvending machine without having to replace an existing fluorescentballast.
 13. The lamp of claim 1 further comprising a wireless interfaceutilized in conjunction with a wireless remote control.
 14. The lampassembly of claim 1 wherein the vending machine socket is a standardfluorescent socket, and the lamp assembly further comprises pinterminals at each end compatible with mounting into the standardfluorescent socket.
 15. The lamp assembly of claim 1 wherein the controlcircuit further comprises a current regulator circuit which eliminatesvariations between different fluorescent ballasts.
 16. The lamp assemblyof claim 1 wherein the control circuit communicates with a vendingmachine controller and receives the control signals from the vendingmachine controller.
 17. A method of retrofitting a vending machineemploying a fluorescent lamp mounted in a fluorescent lamp socket in thevending machine, the method comprising: removing the fluorescent lamp;and replacing the fluorescent lamp with a lamp assembly comprising oneor more light emitting diodes, and a control circuit connected to thediodes, and to a source of power, the diodes and the circuit housed in alamp housing having terminations adapted to be mounted in thefluorescent lamp socket, the control circuit further comprising acommunications circuit for receiving control signals, the controlcircuit selectively controlling adjustment of the illumination providedby the plurality of light emitting diodes based upon said controlsignals.
 18. The method of claim 17 further comprising: providing thecontrol signals by a vending machine controller.